The land use in the Tangale-Waja area is analysed according to the two basic categories of geography: Firstly the manifold interaction between men and environment which form the spatial characteristics of an area, and secondly the decrease of influence with increasing distance. The importance of these two elementary factors is described by indicators as accessibility for the period from the precolonial situation until the time after World War II, when new roads were constructed through the mountainous area. Living in a hilly environment the self contained population (formerly called "hill pagans") had developed special agricultural techniques which can be considered ecologically well adapted. The opening up of the area after the pacification, Christianity and education, led to a considerable increase in population, the expansion of land under cultivation, and the change of settlement structure by down-hill population movement. This resulted in overuse of the fragile natural resources. The size of farm steads became too small for the family unit and the still low accessibility of the hinterland of the main interregional roads as well as inappropriate techniques of agricultural production are shortcomings causing heavy damage to the physical environment and decreasing living standards of the local population.

The account of Borno's war with Mandara thus recounted above, at least from the point of view of the Mandara Chronicler, and all the other accounts I have given above clearly portray to us the essence of the Mune in that oppression and/or a war of caprice is not enjoined. And the war against Mandara was clearly a war of caprice, as Mandara had clearly recanted on its recalcitrance, when threatened. The essence of the Chronicle itself, however, is that we are here seeing, from accounts of an eye-witness, the portrayal of a polity whose language principles and practice of diplomacy, in war and in peace, are not less developed than any we have seen in the states of Euro-Germanic experience, of comparable times. The basis of this well ordered art is essentially the Mune, even though in its universalist form we may wish to assign it to the Book and the Sunna of Islam. Why not then, should we not regard the Mune as the constitution of the pre-colonial Borno State? Munen - ba (not in the Mune), for the Sayfawa ruler is certainly more binding than most modern constitutions had been binding on leaders of present-day African States!

The Lake Chad Basin is a major geographical region in the central part of the Sudan zone of Africa. The northern parts, however, extend into the Sahel and the southern parts of the Sahara desert. It consists of an extensive shallow depression of about 1.536.000 km2 (600.000 miles2) of which about 10% lies in Nigeria. The greater part is shared between the three countries of Cameroon, Chad and Niger. Climatically and agriculturally, the Chad Basin lies within the dry or semi-arid zone of Nigeria. It is a marginal area which has experienced severe droughts and considerable environmental changes in recent years. The natural environment, its use and misuse, and the threat of life posed by environmental pollution dominate discussions on environmental change. But in addition to the natural or physical environment, there are other equally important 'environments' which deserve some attention in view of the role that they play in generating economic growth and in ensuring sustainable development which is the central issue in our concern about the environment. These other environments are the cultural environment, the political environment and the economic environment, both internal and external. In the Chad Basin, all these other environments, along with the natural environment have been greatly influenced by its land locked location in the heart of Africa.

Yerwa is the last of the Borno capitals. Although established in the first decade of colonial administration, it cannot be compared with the many other towns like Fort Lamy, Jos, Kaduna, Niamey et al. which all developed about the same time. Colonial interference with the development of Yerwa appears restricted, mainly, to insistence upon wider roads than a Borno town otherwise would have featured and resettlement schemes, e.g. Mafoni, Ari Askeri. The following is based on the premise that as the town - despite time and political circumstances of its emergence - is a distinctive Borno town, also occupational diversification and structure are distinctively related to urban Borno culture.